Rotatable grip assembly for golf clubs

ABSTRACT

A golf club grip assembly has an upper grip fixedly mounted to a hollow shaft of a golf club, and a substantially identical lower grip, interchangeably mountable with the upper grip, and rotatable relative to the upper grip and the shaft. A selection of lower and upper mounting members which are interchangeable between the upper and lower grips are provided to accommodate a variety of sizes and shapes. A top mounting member encloses the top openings of the upper grip and shaft, is coupled to the upper grip at an annular recess, and is coupled to the inner surface of the hollow shaft at a plug comprising engaging surfaces. A user generally places a substantial portion of one hand on the rotatable lower grip and the other hand on the fixed upper grip. Upon swinging the club and hitting a ball, the lower grip, and thus the one hand, rotates relative to the upper grip and club shaft.

FIELD OF THE INVENTION

[0001] The present invention relates to grips for golf clubs and other sporting equipment, and more particularly, to grip assemblies having one hand grip rotatable relative to another hand grip.

BACKGROUND INFORMATION

[0002] Various prior art golf club designs employ rotatable grip assemblies comprising sleeves, one of which is rotatable on a golf club shaft during a golf swing, and another one of which is substantially fixed to the golf club shaft. For example, U.S. Pat. No. 1,544,226 to De Bus (“the '226 patent”) shows in FIG. 2 a golf club grip having a relatively stationary portion 1 and a rotatable sleeve 5. One drawback associated with the design of the '226 patent is that the relatively stationary portion 1 is not interchangeable with the rotatable sleeve 5, and the sleeve 5 must be custom made for a golf club shaft 2 of given dimensions.

[0003] Similarly, U.S. Pat. No. 1,305,952 to Suesman (“the '952 patent”) shows a golf club having a rotatable grip portion (“C”) and an immovable grip portion (“B”). One drawback associated with the design of the '952 patent is that the rotatable portion C does not have outside dimensions equal to those of the fixed portion B, and the inside dimensions of the grip sections disclosed by the '952 patent are entirely dissimilar. Thus, the '952 patent requires the manufacture of at least two different primary grip sections for a single golf club grip assembly. Another drawback of the design of the '952 patent is that the grips are not interchangeable between shafts of different dimensions.

[0004] The following other patents relate generally to the concept of a rotatable golf club grip with a fixed section and a rotatable section: U.S. Pat. No. 2,225,839 to Moore (“the '839 patent”), U.S. Pat. No. 3,804,413 to Hrivnak (“the '413 patent”), U.S. Pat. No. 3,834,714 to Smolinski (“the '714 patent”), and U.S. Pat. No. 5,413,339 to Martin (“the '339 patent”). One general disadvantage of these prior art patents is that a fixed grip section is not manufactured to be interchangeable with a rotatable grip section, thus requiring design, manufacture, and inventory of additional parts. Another general disadvantage of the above-referenced prior art patents is that they require that grips be specifically manufactured for a given shaft geometry.

[0005] U.S. Pat. No. 4,365,807 to Melby (“the '807 patent”) and U.S. Pat. No. 4,826,168 to McGuire (“the '168 patent”) show adjustable golf club grips which are not rotatable during a swing. The grips of these patents have many of the disadvantages of generally non-rotatable grips in that they include no means for isolating the twisting motions of a user's primary hand during a golf swing. These grips are only adjustable prior to making a swing, and are fixed relative to a golf club shaft during a swing.

[0006] Accordingly, it is an object of the present invention to overcome the above-described drawbacks and disadvantages of the prior art.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to a golf club grip assembly having an upper grip fixedly mounted to a golf club shaft, and a lower grip, interchangeably mountable with the upper grip, spaced below the upper grip, and rotatable relative to the upper grip and the golf club shaft. The grips are interchangeably mountable in the sense that a given grip may be mounted in the position of a lower or an upper grip without change to ancillary components, nor loss of functionality. The grip assembly further comprises lower and upper mounting members that are interchangeably mountable between the upper grip and the lower grip. A top mounting member enclosing a top opening of the upper grip and affixed to a golf club shaft is coupled to the upper grip at an annular recess, and is coupled to the inner surface of the hollow golf club shaft at a plug comprising integrally molded engaging surfaces.

[0008] One advantage of grip assemblies embodying the present invention is that they are rotatable during a user's golf swing, as opposed to being merely adjustable prior to a user's swing. Thus, grips of the present invention are capable of isolating the twisting motions of a user's primary hand during a golf swing.

[0009] Another important advantage of the present invention is that the substantially fixed grip portion is interchangeably mountable with the rotatable grip portion. Therefore, only one type of grip portion need be manufactured, stocked, or supplied in order to practice the invention on a given golf club.

[0010] Another advantage of the present invention is that the upper and lower mounting members of the grip assembly permit any one interchangeably mountable upper or lower grip to be adapted for use on a vast variety of golf club shafts of various shapes and sizes, thus dividing design, manufacture, and inventory requirements for the upper and lower grips themselves by a factor far greater than two.

[0011] Other objects and advantages of the present invention will become apparent in view of the following detailed description of the preferred embodiments and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a side elevational view of a rotatable golf club grip assembly embodying the present invention, mounted on a typical golf club comprising a shaft and a head.

[0013]FIG. 2 is an exploded side elevational view of the rotatable golf club grip assembly of FIG. 1 with the shaft and club head removed for clarity.

[0014]FIG. 3 is a cross-sectional view taken along the line A-A of FIG. 1.

[0015]FIG. 4 is a side elevational view of a rotatable golf club grip assembly similar to that depicted in FIG. 1, but further comprising a locking mechanism embodying the present invention.

[0016]FIG. 5 is an exploded side elevational view of the rotatable golf club grip assembly of FIG. 4 with the shaft and club head removed for clarity.

[0017]FIG. 6 is a top plan view of the lower mounting member of the grip assembly of FIGS. 4 and 5 taken along line 6-6 of FIG. 5.

[0018]FIG. 7 is a bottom plan view of the locking ring of the grip assembly of FIGS. 4 and 5 taken along line 7-7 of FIG. 5.

[0019]FIG. 8 is a side elevational view of another embodiment of the rotatable golf club grip assembly of the present invention without exterior ribs and comprising an alternate end cap.

[0020]FIG. 9 is an exploded side elevational view of the rotatable golf club grip assembly of FIG. 8 with the shaft and club head removed for clarity.

Detailed Description of the Preferred Embodiments

[0021] In FIGS. 1 and 2, a first preferred embodiment of a golf club grip assembly embodying the present invention is indicated generally by the reference numeral 10. The grip assembly 10 comprises a lower grip 12, an upper grip 14 which is substantially identical to the lower grip 12, a lower mounting member 16, an upper mounting member 18, a bottom mounting member 20, and a top mounting member in the form of an end cap 22. The lower grip 12 defines a plurality of ribs 24 on an exterior surface thereof, and the upper grip 14 similarly defines a plurality of ribs 26 on an exterior surface thereof. The grip assembly 10 is mounted on a golf club shaft 27 having attached to one end thereof a club head 28 defining a striking face 29. As shown in FIGS. 1 and 3, the striking face 29 defines a plane “B” which is approximately perpendicular to a plane “A” extending between the outermost surfaces of two adjacent ribs 24, 26. The ribs 24, 26 extend in the axial direction of each grip, and are spaced relative to each other to define recesses therebetween to enable a user to place his or her thumb or other fingers between or across the recesses for convenient and repeatable orientation of the striking face 29 relative to the user's hand.

[0022] With reference to FIG. 2, the lower grip 12 further defines an elongated hollow 30 formed by a cylindrical interior surface extending from one end of the grip to the other, a countersunk cylindrical relief 32 at one end, and an annular protrusion 34 at the other end. The upper grip 14 similarly defines an elongated hollow 36 formed by a cylindrical interior surface extending from one end of the grip to the other, a countersunk cylindrical relief 38 at one end, and an annular protrusion 40 at the other end. As shown typically in FIGS. 1 and 2, the lower and upper grips 12 and 14 define the same shapes and dimensions, and therefore may be interchangeably mounted on the golf club shaft 27. Thus, the grip assembly of the present invention may be made, if desired, with a single part defining both the upper and lower grips. In the preferred embodiments of the present invention, the upper and lower grips are made of a resilient polymeric material, and preferably, are injection molded in the same mold (or substantially identical mold cavities).

[0023] As also shown in FIG. 2, the lower mounting member 16 defines an annular lower mounting surface 42 having a subordinate outer diameter substantially equal to the inner diameter of the relief 32 of the lower grip 12, in order to allow the annular mounting surface to be slidably received within the lower grip. The lower mounting member 16 further defines an annular lower bearing surface 44 having a superior outer diameter for slidably contacting the upper mounting member 18, and an interior mounting surface 43 having a substantially cylindrical shape dimensioned to be slidably received over the golf club shaft 27. The upper mounting member 18 similarly defines an annular upper mounting surface 46 having a subordinate outer diameter substantially equal to an inner diameter of the relief 38 of the upper grip 14 in order to allow the annular mounting surface to be slidably received within the upper grip. The upper mounting member 18 further defines an annular upper bearing surface 48 having a superior outer diameter substantially equal to the superior outer diameter of the lower bearing surface 44 for slidably contacting the lower mounting member 16, and an interior mounting surface 45 having a substantially cylindrical shape dimensioned to be slidably received over the golf club shaft 27. In the illustrated embodiment of the present invention, the lower and upper mounted members 16 and 18, respectively, are substantially identical in size and shape. However, as will be recognized by those skilled in the pertinent art based on the teachings herein, the upper and lower mounting members may be shaped and/or dimensioned differently relative to each other in order to mount the identical upper and lower grips onto shafts of different sizes and shapes.

[0024] As also shown in FIG. 2, the bottom mounting member 20 defines a substantially cylindrical mounting surface 50 extending through the interior of the mounting member and dimensioned to be slidably received on the golf club shaft 27. The bottom mounting member 20 further defines a bottom countersunk cylindrical relief 52 dimensioned to slidably receive therein the annular protrusion 34 of the lower grip 12, and a bearing surface 53 on the upper end thereof for the slidably contacting opposing surface of the lower grip 12.

[0025] The top mounting member 22 defines a cap portion 54, and an annular recess or channel 56 formed in the cap for receiving the annular protrusion 40 of the upper grip 14. A generally cylindrical plug 58 of the top mounting member 22 projects outwardly from the cap portion 54, and a plurality of engaging ribs or like projecting surfaces 60 are spaced relative to each other on the exterior surface of the plug for engaging the interior surface of the hollow club shaft 27 and thereby fixedly securing the cap to the shaft.

[0026] In order to assemble the grip assembly 10 to the golf club shaft 27, the top mounting member or end cap 22 is affixed to the shaft by slidably inserting the plug 58 into the hollow end of the shaft. The top mounting member 22 is preferably made of a relatively resilient polymeric material, and therefore the ribs 60 of the plug 58 flexibly engage the interior surfaces of the shaft to fixedly secure the plug to the shaft. If desired, an adhesive of a type known to those skilled in the pertinent art may be applied to the plug to further secure the end cap 22 to the shaft. In accordance with a first preferred method for assembling the grip assembly to the shaft, the parts of the grip assembly are initially slipped over the opposite end of the shaft prior to attachment of the club head thereto. Accordingly, the upper grip 14 is slidably mounted over the top portion of the shaft 27 with the annular protrusion 40 of the upper grip received into the annular channel of the end cap 22. If desired, a pressure sensitive adhesive tape and/or adhesive of the type known to those skilled in the pertinent art for performing the functions described herein may be applied between upper grip 14 and the shaft 27, or may be applied between only select portions of the upper grip and shaft to further secure the upper grip to the shaft and prevent these parts from rotating relative to each other. The upper mounting member 18 is slidably received onto the shaft 27 with the upper mounting surface 46 received into the recess 38 of the upper grip. As described above, the interior mounting surface 45 of the upper mounting member 18 is preferably dimensioned to slidably contact the underlying portion of the shaft 27 to mount the upper grip to the shaft and further prevent relative movement between the upper grip and shaft. However, if necessary, a pressure-sensitive adhesive tape of a type known to those skilled in the pertinent art may be attached between the club shaft and upper mounting member 18 to fill any space between the mounting member and shaft, and, in turn, fixedly secure the mounting member to the shaft.

[0027] The lower mounting member 16 is slidably mounted over the shaft 27 with the lower bearing surface 44 slidably contacting the corresponding surface 48 of the upper mounting member 18. The lower grip 12 is slidably mounted over the shaft 27 below the lower mounting member 16 with the mounting surface 42 of the lower mounting member slidably received within the recess 32 of the lower grip. As indicated above, the lower and upper grips 12 and 14, respectively, are preferably made of a flexible polymeric material. Accordingly, as also indicated above, the annular surface 42 of the lower mounting member 16 and recess 32 of the lower grip 12 are dimensioned to allow the grip to frictionally engage the lower mounting member and thereby prevent relative rotation of the parts. As a result, the lower grip 12 and lower mounting member 16 rotate as a unit relative to the upper grip 14 and upper mounting member 18.

[0028] The bottom mounting member 20 is slidably mounted over the shaft 27 with the annular protrusion 34 of the lower grip 12 received within the recess 52 of the bottom mounting member, and the bearing surface 53 of the bottom mounting member slidably contacting the opposing surface of the lower grip. The recess 52 of the bottom mounting member and annular protrusion 34 of the lower grip are dimensioned relative to each other to allow the annular protrusion to freely rotate within the recess. The cylindrical mounting surface 50 of the bottom mounting member is fixedly secured to the shaft 27 with adhesive tape and/or other adhesive (not shown). Accordingly, the lower grip 12 and lower mounting member 16 are allowed to freely rotate relative to the other components of the grip assembly which are fixedly secured to the golf club shaft.

[0029] In accordance with a second preferred method for assembling the grip assembly 10 to the golf club shaft 27, adhesive tape or like spacer material is applied to the shaft 27 at the locations where the mounting surfaces of the grip assembly are to be attached in order to increase the effective diameter of the shaft where necessary, and the parts of the grip assembly 10 are slidably mounted over the end of the shaft opposite the club head. Accordingly, adhesive tape is preferably applied to the shaft at the desired location of the bottom mounting member 20, and the bottom mounting member is then slidably mounted over the adhesive tape and fixedly secured to the shaft by the tape. Then, the lower grip 12 is slidably mounted over the shaft, and the annular protrusion 34 of the lower grip is slidably received within the recess 52 of the bottom mounting member as described above. The lower mounting member 16 is then slidably mounted over the shaft 12 with the annular mounting surface 42 received within the recess 32 of the lower grip and frictionally engaging the grip to allow the lower grip and lower mounting member to rotate as a unit relative to the shaft and other components of the grip assembly. The upper mounting member 18 and upper grip 12 are then mounted to the shaft 27 in the manner described above with adhesive type or like adhesive mechanism interposed between the mounting member and/or grip and the shaft to fixedly secure the components to the shaft, and prevent relative rotation of the grip and shaft. Preferably, the upper grip 14 is aligned with the striking face 29 of the club head so that the plane “A” formed between the outermost surfaces of two adjacent ribs 24, 26 is substantially perpendicular to the plane “B” defined by the striking face. The step of aligning the upper grip 14 may be accomplished by placing a planar 90 degree square simultaneously against the striking face 29 and the shaft 27, and rotating the grip 14 until the plane formed between the two adjacent ribs is perpendicular to the plane of the square. The top mounting member or end cap 22 is then secured to the end of the hollow shaft in the same manner as described above to further secure the grip assembly to the shaft.

[0030] The operation of the grip assembly of the invention is hereinafter described with reference to a user's primary and secondary hands, where the primary hand is the right hand for a user who golfs or plays “right-handed”, or the left hand for a user who golfs or plays “left-handed”. In operation, a user places a secondary hand on the upper grip portion 14 and a substantial portion of the primary hand on the lower grip portion 12. An especially desirable hand position may be achieved when the user places the thumb of the secondary hand between the two adjacent ribs 26 which form the plane “A” substantially perpendicular to the plane “B” of the striking face 29 of the golf club head 28. This structure permits convenient and repeatable orientation of the user's thumb relative to the striking face 29. Upon swinging a club and hitting a ball, the rotatable sub-assembly comprising the lower grip portion 12 and the lower mounting member 16, and thus the primary hand, is permitted to rotate relative to the substantially fixed sub-assembly comprising at least the upper grip portion 14 and the golf club shaft 27, and thus the secondary hand. In the particular embodiment of FIGS. 1 through 3, the lower mounting member 16 rotates relative to the substantially fixed upper mounting member 18, and the lower grip portion 12 rotates relative to the substantially fixed bottom mounting member 20. The upper mounting member 18, and all components above it are substantially fixed, as are the bottom mounting member 20 and all components below it. As a result, any twisting effect of the user's primary hand is substantially negated by the swivel or rotating action of the lower grip 12, thus facilitating the user's ability to hit the ball in the desired direction, as opposed to a slice or hook.

[0031] In FIGS. 4 through 7, a second preferred embodiment of the golf club grip assembly of the present invention is indicated generally by the reference numeral 110. The grip assembly 110 of FIGS. 4 through 7 is substantially similar to the grip assembly 10 of FIGS. 1 through 3, and therefore like reference numerals preceded by the numeral 1 are used to indicate like elements. The primary difference between the grip assembly 110 and the grip assembly 10 described above, is that the grip assembly 110 includes means for selectively locking the position of the lower grip 112, and thereby preventing relative rotation between the lower and upper grips. In addition, as can be seen, the ribs 124 and 126 of the grips 112 and 114, respectively, define a different configuration than do the ribs shown in FIGS. 1 and 2. However, the grips 112 and 114 remain interchangeably mountable with each other as well as individually interchangeable with the grips of other preferred embodiments, such as the grips 12 or 14 of FIGS. 1 through 3. Otherwise, the assembly and operation of the grip assembly 110 is essentially the same as that described above in connection with the grip assembly 10.

[0032] As shown in FIG. 5, the bottom mounting member 120 is essentially the same as the bottom mounting member 20 described above; however, the bottom mounting member 120 defines a pair of locking surfaces 155 spaced relative to each other on the annular surface defining the cylindrical relief 152, and projecting radially inwardly toward the axis of the mounting member and club shaft. As shown best in FIGS. 5 and 7, the grip assembly 110 further includes a locking ring 121 defining a cylindrical recess 162 formed on one side thereof for receiving an annular protrusion 134 of the lower grip 112, and a locking detent 164 projecting outwardly from the opposite side of the locking ring in the axial direction thereof, and a central aperture 166 is formed through the locking ring to slidably mount the locking ring over the club shaft 127.

[0033] As can be seen, when assembled, the protrusion 134 of the lower grip 112 is received within the annular recess 162 of the locking ring to fixedly secure the lower grip to the locking ring. Preferably, the lower grip is made of a relatively resilient polymeric material allowing the protrusion 134 to frictionally engage the annular recess 162 of the locking ring. However, if desired, the lower grip 112 may be adhesively or otherwise attached to the locking ring. In addition, the locking detent 164 is received within the recess 152 of the lower mounting member 120, and thereby allows the lower grip 112 to rotate relative to the bottom mounting member. However, when the locking detent 164 is rotated into engagement with the locking surfaces 155, and if sufficient rotational force is applied to push the locking detent between the two locking surfaces 155, the locking surfaces may frictionally retain the locking detent and, in turn, lock the position of the locking ring and lower grip in place. The user may then unlock the lower grip 112 by simply twisting the lower grip with sufficient force to release the locking detent 164 from the locking surfaces 155. As will be recognized by those skilled in the pertinent art based on the teachings herein, numerous different mechanisms which are currently or later become known to those skilled in the pertinent art may be employed to perform the function of the locking ring and locking surfaces described herein. In addition, if desired, a visual and/or tactile indicator may be applied to the exterior surfaces of the locking ring, lower grip, and/or other components of the grip assembly 110 in order to visually indicate whether the lower grip is locked or unlocked. For example, when in an unlocked position, the components could be rotated to reveal a visually prominent colored strip, alignment mark or other indicator to reveal the unlocked condition of the grip assembly. Then, when rotated into the locked position, the colored strip or other visual indicator would be automatically concealed, or would reveal a color strip or indicator of another color, to show that the grip is in the unlocked position. Accordingly, numerous different such indicators which now or later become known for performing such function equally may be employed.

[0034] The preferred methods for assembling the grip assembly 110 to the golf club shaft 127 are substantially similar to the methods described above in connection with the previous embodiment. However, the locking ring 121 also must be assembled to the club shaft 127 as described above and illustrated in the drawings.

[0035] In operation, the grip assembly 110 may be utilized in a manner similar to the grip assembly 10. One difference, however, is that the normally rotatable lower grip 112 may be locked by a user to substantially prevent rotation relative to the upper grip 114 and the golf club shaft 127. As discussed above, this is accomplished by rotatably positioning the detent 164 of locking ring 121 between the locking surfaces 155 of bottom mounting member 120. Another difference is that when the locking ring 121 is in an unlocked position, the ring will rotate with the lower grip 112 relative to the bottom mounting member 120 during play. Upon swinging a club and hitting a ball, the rotatable sub-assembly comprising the lower grip portion 112, the locking ring 121, and the lower mounting member 116, and thus the primary hand, is permitted to rotate relative to the substantially fixed sub-assembly comprising at least the upper grip portion 114 and the golf club shaft 127, and thus the secondary hand. In the particular embodiment of FIGS. 4 through 7, the lower mounting member 116 rotates relative to the substantially fixed upper mounting member 118, and the lower grip portion 114 and locking mechanism 121 rotate relative to the substantially fixed bottom mounting member 120.

[0036] In FIGS. 8 and 9, another golf club grip assembly embodying the present invention is indicated generally by the reference numeral 210. The grip assembly 210 is substantially similar to the grip assembly 10 of FIGS. 1 through 3, and therefore like reference numerals preceded by the numeral 2 are used to reference like elements. The primary differences between the grip assembly 210 and the above-described grip assembly 10 are embodied by the grips 212 and 214, and the top mounting member in the form of an end cap 222. As shown best in FIG. 8, the grips 212 and 214 differ from the grips 12 and 14 in that they lack external ribs. However, like the grips described above, each of the grips 212 and 214 define approximately equal outer diameters on opposite ends of each grip. Similarly, as shown in FIG. 8, the interior surface 230 of each grip defines a slight taper from one end to the other in order to have sufficient draft to release itself from the mold. In addition, the end cap 222 does not include a plug, but rather is simply adhesively attached to the end portion of the upper grip 214 by inserted in the annular protrusion 240 into the recess 256 of the end cap. If desired, an adhesive may be employed to fixedly secure the end cap to the upper grip. Thus, the end cap 222 may be mounted on a golf club shaft 227 having a solid end. Otherwise, the methods of assembly of the golf club grip assembly 210 are substantially similar to those described above in connection with the previous embodiments. In operation, the grip 210 of FIGS. 8 and 9 operates in a manner substantially similar to that of the grip 10 of FIGS. 1 through 3, except that there are no ribs for placing a user's thumb therebetween.

[0037] Accordingly, one advantage of the grip assemblies of the present invention is that they are rotatable during a user's golf swing, as opposed to being merely adjustable prior to a user's swing. Thus, grips of the present invention are capable of isolating the twisting motions of a user's primary hand during a golf swing.

[0038] Although prior art references show the basic concept of a golf club grip having a rotatable portion in addition to a fixed portion, none show both rotatable and fixed grips interchangeably mountable on a golf club shaft. Therefore, another advantage of the present invention is that the grips disclosed are interchangeably mountable as either the fixed or rotatable portions on a golf club shaft. Such interchangeability of the largest or most expensive parts of the rotatable grip of the present invention allows for reduced manufacturing costs as well as reduced replacement parts inventory requirements, among other advantages recognizable by those skilled in the pertinent art. Therefore, only one type of grip portion need be manufactured, stocked, or supplied in order to practice the invention on a given golf club.

[0039] Another advantage of the present invention is that the only parts which are individually selected for application to a given golf club shaft of a particular shape or diameter are the small and inexpensively manufactured mounting members. In fact, these mounting members are so inexpensive to manufacture that a plurality of such mounting members may be included in a retail rotatable grip retrofit kit at negligible additional expense, thereby facilitating simple installation of a grip embodying the present invention on a multitude of different golf club shafts. Accordingly, several sets of upper and lower mounting members, and bottom mounting members may be supplied with each pair of identical upper and lower grips, wherein each set of three mounting members defines respective internal diameters (or other requisite internal shapes and/or dimensions) for slidably contacting a respective size and/or type of golf club shaft. Accordingly, the grip assembly of the present invention is uniquely adapted to provide one rotatable grip assembly usable with virtually any size and/or configuration of golf club shaft

[0040] Another advantage of a preferred embodiment of the present invention is that the inside dimensions of the rotatable and fixed grip sections are substantially equal. Thus, upper and lower mounting members may each be selected from the same group of mounting members having identical outer mounting surfaces but varied inner mounting surfaces for mounting on golf club shafts of various shapes and sizes. This single feature may reduces the inventory requirements for these mounting members by up to about 50%.

[0041] A further advantage is that the upper and lower mounting members of the present invention allow a single, interchangeably mountable upper or lower grip to be adapted for use on a vast variety of golf club shafts of various shapes and sizes, thus dividing design, manufacture, and inventory requirements for the upper and lower grips themselves by a factor far greater than two.

[0042] Yet another advantage of a preferred embodiment of the present invention is that the top mounting member is connectable to two other substantially fixed components on two separate surfaces, thereby providing for an attachment capable of withstanding forces in excess of those which might cause a mounting member connectable to only one component or connectable on only one surface to lose adhesion. The integral engaging surfaces of the top mounting member embodying the present invention are also believed to provide for better adhesion than available under the prior art.

[0043] Another advantage of the present invention is that a user may be able to hit a golf ball farther and straighter with a rotatable grip comprising the present invention than with a conventional fixed or adjustable grip.

[0044] Another advantage of the present invention is that the rotatable or lower grip portion has outside dimensions substantially equal to those of the fixed or upper grip portion, allowing for approximately equal wraparound of a typical user's hands. This may be a significant advantage for players that tend to grip the shaft on the lower portion of the grip, particularly when hitting relatively short strokes.

[0045] Yet another advantage of the present invention is that injuries to users' muscles and joints may be generally reduced by providing a rotatable grip to reduce the stress of opposing inputs from one hand tending to twist a rigid golf club shaft while the other hand resists the twisting motion.

[0046] As will be recognized by those of ordinary skill in the pertinent art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present invention without departing from its scope as defined in the appended claims. For example, a locking mechanism may be mounted at the upper end of the lower grip to supplement or replace the locking mechanism 121 described above. Adjustable locking mechanisms also may be used, such as, for example, a first limiting surface affixed to the lower grip and a second limiting surface adjustably affixed by a threaded collar to the golf club shaft, wherein the first and second limiting surfaces define longitudinally offset cams of generally elliptical surface and cylindrical cross-section, axially aligned with the golf club shaft for limiting the angular rotation of the lower grip relative to the upper grip. Alternatively, a grip assembly having lower and upper bearing surfaces defining longitudinally offset arc sections may be used for limiting the angular rotation of the lower grip relative to the upper grip.

[0047] Also, the upper and lower mounting members or supports therefor could be split along a longitudinal axis to facilitate ease of installation on a golf club shaft or to promote a snug fit on shafts having irregular shapes. Alternatively, a washer of suitable thickness and of lesser outer diameter than the superior outer diameters of the lower and upper mounting members, but of greater inner diameter than that of the lower and upper mounting members, could be recessed between the upper and lower mounting members in order to positively center the lower mounting member relative to the upper mounting member. If desired, a lower grip of any or no rib design may be paired with a different type upper grip of no or any rib design in order to suit individual tastes or applications. Likewise, grips of substantially identical dimensions may be manufactured to achieve a particular hardness or compliance to suit individual tastes or applications. These and other variations recognizable to those skilled in the pertinent art may be made to a golf club grip assembly embodying the present invention without departing from the scope and spirit of the invention. Accordingly, this detailed description of preferred embodiments is to be taken in an illustrative as opposed to a limiting sense. 

What is claimed is:
 1. A grip assembly for a golf club, comprising: a lower grip and an upper grip, each grip defining an elongated hollow therethrough for receiving a golf club shaft, and being interchangeably mountable on the shaft with the other grip; a lower bearing surface coupled to the lower grip and facing the upper grip; and an upper bearing surface coupled to the upper grip and facing the lower grip, wherein the lower and upper bearing surfaces slidably contact each other to permit rotation of the lower grip relative to the upper grip, and the upper grip includes at least one mounting surface for fixedly coupling the upper grip to the golf club shaft and preventing rotation of the upper grip relative to the shaft.
 2. A grip assembly as defined in claim 1 , wherein the upper and lower grips are substantially identical.
 3. A grip assembly as defined in claim 1 , further comprising: a lower mounting member mountable between the lower grip and the shaft and defining the lower bearing surface; and an upper mounting member mountable between the upper grip and the shaft and defining the upper bearing surface.
 4. A grip assembly as defined in claim 3 , wherein the lower mounting member and the upper mounting member are interchangeably mountable between the upper grip and the lower grip.
 5. A grip assembly as defined in claim 1 , comprising: a plurality of first mounting members for mounting the upper grip to the shaft, each first mounting member defining an approximately cylindrical mounting surface for slidably mounting the first mounting member on a golf club shaft between the upper grip and the shaft, and wherein at least a plurality of the first mounting members define different sized cylindrical mounting surfaces relative to each other for mounting the upper grip to any of a plurality of different sized club shafts; and a plurality of second mounting members for mounting the lower grip to the shaft, each second mounting member defining an approximately cylindrical mounting surface for slidably mounting the second mounting member on a golf club shaft between the lower grip and the shaft, and wherein at least a plurality of the second mounting members define different sized cylindrical mounting surfaces relative to each other for mounting the lower grip to any of a plurality of different sized club shafts.
 6. A grip assembly as defined in claim 3 , wherein the lower and upper mounting members have outer dimensions substantially identical to one another.
 7. A grip assembly as defined in claim 1 , wherein at least one of the upper and lower grips defines an outer surface having a first end and a second end, the first end having an outer diameter and the second end having an outer diameter, and the outer diameters at each end being substantially equal.
 8. A grip assembly as defined in claim 1 , further comprising means for limiting the angular rotation of the lower grip relative to the upper grip.
 9. A grip assembly as defined in claim 1 , further comprising at least one locking member coupled to at least one end of the lower grip for selectably preventing rotation of the lower grip relative to the upper grip.
 10. A grip assembly as defined in claim 1 , further comprising a top mounting member fixedly mounted to the upper grip and enclosing an inner surface thereof at one end.
 11. A grip assembly as defined in claim 10 , wherein the top mounting member defines an annular channel for receiving an end of the upper grip.
 12. A grip assembly as defined in claim 10 , wherein the golf club shaft is hollow and the top mounting member has a center portion fixedly mountable within the hollow of the golf club shaft.
 13. A grip assembly as defined in claim 12 , wherein the top mounting member further comprises a plurality of engaging surfaces approximately concentric with a longitudinal axis of the plug and located substantially on the outer surface of said plug.
 14. A grip assembly as defined in claim 1 , further comprising a bottom mounting member coupled to the lower grip which is slidably mounted on at least one of the lower grip and the golf club shaft.
 15. A grip assembly as defined in claim 1 , wherein at least one of the upper and lower grips further comprises a plurality of exterior ribs spaced relative to each other and defining a plurality of recesses therebetween.
 16. A grip assembly as defined in claim 1 , wherein the upper and lower grips each further comprises a plurality of exterior ribs spaced relative to each other and defining a plurality of recesses therebetween, and wherein the ribs of the lower grip are rotatably alignable with the ribs of the upper grip.
 17. A grip assembly as defined in claim 1 , wherein: the golf club shaft is coupled to a golf club head defining a striking face; the upper grip comprises at least two exterior ribs spaced relative to each other and defining a first plane extending between the outermost surfaces of two adjacent ribs; and the first plane is approximately perpendicular to a second plane substantially defined by the striking face of the golf club head.
 18. A grip assembly for a golf club, comprising: first means for gripping a golf club, said first means being slidably mountable on a golf club shaft and rotatable relative thereto; second means for gripping a golf club, said second means being slidably mountable on the golf club shaft, interchangeably mountable with the first means, and fixedly secured to the golf club shaft to prevent rotation of the second means relative go the golf club shaft; third means coupled to the first means and facing the second means for slidably contacting at least one of the second means and the golf club shaft to facilitate rotation of the first means relative thereto; and fourth means coupled to the second means and facing the first means for slidably contacting the third means to facilitate rotation of the first means relative to the second means and golf club shaft.
 19. A grip assembly for a golf club, further comprising means for means for locking the position of the first means and thereby preventing rotation of the first means relative to the second means and golf club shaft. 